Battery potential energy versus mass

Click For Summary
SUMMARY

The discussion centers on the relationship between energy extraction from a battery and the corresponding reduction in mass, specifically in the context of a 120 Ah, 12V lead-acid battery. It is established that discharging the battery results in a mass loss of approximately 60 nanograms, calculated using Einstein's mass-energy equivalence (E=mc²). However, measuring this minuscule change in mass is deemed impractical due to the required precision of about 12 digits, far exceeding typical measurement capabilities.

PREREQUISITES
  • Understanding of Einstein's mass-energy equivalence (E=mc²)
  • Familiarity with battery specifications, particularly lead-acid batteries
  • Knowledge of precision measurement techniques
  • Basic principles of energy conversion in electrical systems
NEXT STEPS
  • Research advanced precision measurement techniques for small mass changes
  • Explore the implications of mass-energy equivalence in practical applications
  • Study the energy output characteristics of various battery types
  • Investigate the thermal losses in battery discharge processes
USEFUL FOR

Physicists, electrical engineers, battery technology researchers, and anyone interested in the practical applications of mass-energy equivalence in energy systems.

rcgldr
Homework Helper
Messages
8,946
Reaction score
687
I'm asking this question on behalf of another person who doesn't know english well.

What he wants to know is the relationship between energy extracted from a battery and the corresponding reduction in mass of the battery, and if it would be possible to measure the difference with some type of precise instrumentation rather than than it being an abstract calculation.

Asume that all energy outputs, including electrical and heat related losses are considered in the relationship between reduction of potential energy and reduction of mass.
 
Physics news on Phys.org
Yes, there should be a diminuation in mass of the battery when it discharges, according to relativity. As to be able to measure this, I don't think this is going to be possible, as the change is too small.

120 Ahr at 12V (a serious car lead battery) corresponds to about 5 MJ, which corresponds (mc2) to ~60 nanogram.
I don't think you can see a difference of 60 nanogram on the weight of a car battery of say, 20 kg. You'd need a precision of about 12 digits to start seeing the difference.
 

Similar threads

Undergrad Gravitational potential energy
  • · Replies 46 ·
2
Replies
46
Views
5K
Undergrad System, potential energy, and nonconservative forces
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Potential Energy and Potential -- Systems versus Particles
  • · Replies 6 ·
Replies
6
Views
11K
Undergrad Work-Energy Theorem for Moving Block and Spring System?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad What Does Negative Potential Energy Indicate in Colliding Iron Balls in Space?
  • · Replies 7 ·
Replies
7
Views
2K
High School Is Comparing Binding Energy and Mass to Kinetic and Potential Energy Valid?
  • · Replies 5 ·
Replies
5
Views
2K
Mechanisms Involved When Charging a Battery
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Question about Momentum vs. Kinetic Energy vs. Deforming In Collisions
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad The far reaching ramifications of the work-energy theorem
  • · Replies 31 ·
2
Replies
31
Views
4K
Graduate What exactly is meant by potential energy in the Lagrangian?
  • · Replies 10 ·
Replies
10
Views
2K